The present invention relates generally to an assembly for securing a bearing within a housing, and more particularly, to an improved arrangement for axially and rotatably securing a bearing.
In a typical bearing assembly, a plurality of load-bearing elements, such as rollers or spheres, are disposed between an inner race and a separate outer race to permit the inner and outer race to rotate relative to each other with minimal friction. In a known arrangement, the inner race is attached to and rotates with a shaft while the outer race is secured to a fixed housing. Alternatively, the inner race may be attached to a stationary shaft while the outer race is secured to a rotating housing.
Traditional methods used to secure a bearing within a bearing opening or bore of a housing include the use of a sleeve-like bearing retainer having a coefficient of thermal expansion near to that of the bearing outer race. The outer race of the bearing is pressed into the bearing retainer for frictional engagement therewith. The bearing retainer is received within the bearing opening and may be provided with a radially-extending flange that is bolted or attached by some other suitable means to the housing. This configuration ideally prevents axial movement and prevents rotation of either the bearing outer race or the retainer relative to the housing.
Alternatively, the housing bore may be configured over its axial length to permit insertion of a bearing retainer having a leading end with radially-extending retaining members defining a noncircular overall profile. After the leading end of the bearing retainer is axially inserted through the housing bore to a position axially forward of the bore, the bearing retainer is rotated to an installed orientation in which the retaining members engage the outer surface of the housing to prevent axial movement of the bearing retainer back through the bore. A suitable anti-rotation device, such a pin, bolt or retainer plate having a radially extending tab engaging a flat defined by the bearing retainer, is used to prevent rotation of bearing retainer from its installed orientation.
One of the disadvantages of the bearing retainer arrangements of the aforementioned types is that a separable bearing retainer adds an extra component cost to the bearing assembly. In addition, bearing assemblies using a bearing retainer may be of limited use under certain environmental conditions because they rely solely on thermal expansion material properties to secure a bearing outer race within the bearing retainer. Moreover, the need for means to secure the bearing retainer within a bearing housing, such as a pin or a bolt, may subject these bearing retainer arrangements to physical design constraints that restrict their use in certain applications.
Those skilled in the art have also utilized a locking clip to non-rotatably secure a bearing outer race to a housing. The locking clip is a projecting key fastened within a groove extending across the outer surface of a bearing outer race and extending into a cooperating opposed groove on the inner wall of a housing receiving the bearing outer race. The locking clip arrangement is typically unable to axially secure the bearing outer race relative to the housing and to more permanently secure the bearing against rotation in the housing.
Another known method for axially positioning a bearing within the bore of a guide roller includes the use of projections, such as beads and notches. These projections extend from the guide roller in a radial direction to engage the side of a bearing outer race at several positions about its circumference. An axially directed stamp is used to squeeze material into the bore for the formation of lugs to engage the other side surface of the bearing outer race. The disadvantage of this method is that the bearing is only positioned and securely held axially.
In the area of bearing retention assemblies, there continues to be a need for an inexpensive and simple construction for axially and rotatably securing a bearing relative to a bearing housing.
In one aspect of the invention, a bearing retention assembly is provided. The assembly includes a bearing set having an annular outer race ring. The outer race ring has a plurality of circumferentially spaced cam chamfers on at least one outer circular edge. The assembly also includes a bearing housing for capturing the bearing set. The bearing housing includes at least one integral securing member for interfering with and engaging at least one cam chamfer for axially and rotatably securing the outer race ring relative to the housing.
In another aspect of the invention, the outer race ring of the bearing retention assembly includes at least one annular surface and an outer circular face. The annular surface and the outer circular face define an outer circular edge. The outer race ring further defines a plurality of spaced, outwardly disposed cam chamfers disposed at circumferential locations of the outer circular edge.
In yet another aspect of the invention, a method of axially and rotatably securing a bearing set having an outer race ring within a bearing housing having a bearing opening is provided. The method includes providing a plurality of circumferentially spaced chamfers on at least one outer circular edge of said outer race ring. The bearing opening is provided with at least one inwardly projecting integral securing member at a location of the bearing opening corresponding to a location of at least one cam chamfer. The method further includes press-fitting the bearing set into the bearing housing and deforming the integral securing member radially inwardly sufficiently to engage the corresponding cam chamfer.
In another aspect of the invention, the inner race ring of the bearing retention assembly includes at least one annular surface and an inner circular face. The inner face defines an inner opening. The annular surface and the inner circular face define at least one circular edge. The inner race ring further includes a plurality of spaced, outwardly disposed cam chamfers disposed at circumferential locations of said at least one circular edge.
Other aspects of the invention will be apparent to those skilled in the art in view of the following description in conjunction with the accompanying drawings.